It just seems unpractical and low tech
This is all speculative:
Balloons that size can carry all sorts of equipment. Weather patterns are important for warfare but would be impossible to accurately predict. A baseline is good, however. It could also be tracking radar sweeps to analyze air defense. It could just be seeing what communications are at that altitude. Photography would be the lowest on my list as satellites do that already.
Or it could just be a weather balloon that traversed the US, because that’s the way the wind was going and we shot it down for theatrics with the worry that if we did nothing, it would be used politically.
Who’s to say.
Satellites orbit at hundred of kilometers and can get pretty good images but now imagine those same cameras on satellites.. in a balloon only a few tens of kilometers high. MUCH closer to the surface and can get extremely high resolution..hell if I had to guess you could probably identify a coin on the Floor with such proximity.
Only catch is it is moving a lot so focus could be an issue
This is speculation as I do not know what kind of camera is on board the balloon, could be a average camera not a Satellite grade one for all I know.
Which baffles me as well, my answer would be it there is no benefit at all.
A balloon isn’t better in any categories when it comes to spying. In most cases it doesn’t even beat Google Earth.
A balloon isn’t fast or covert or controllable, or even cheap enough. Quadcopter or fixed-wing drones built with $500 budget can do better than it when Google Earth doesn’t work.
They’re extremely practical because they’re extremely low cost. No pilot, no launch, no propulsion system, just set and forget. And, as we’ve seen, the apparent difference between “spy balloon” and “weather balloon” is just semantics and a dash of international diplomacy.
Edit: also balloons can fly at altitudes that make them impervious to most aircraft interventions, and it’s a conundrum for target nations to decide whether to spend a missile on a balloon.